A fuel cell system has a problem of possible damage that may be caused to pipes and valves when the external temperature is low and water generated inside the fuel cell system becomes frozen after the fuel cell system is stopped. In general, a fuel cell is more difficult to activate than other power sources; and particularly under low temperature, the fuel cell has a problem of inability to supply a desired voltage/current, thereby failing to activate the relevant equipment.
In light of the above-described problem, a method for discharging moisture accumulated inside the fuel cell by executing scavenging processing when the fuel cell system is stopped has been suggested (see, for example, Patent Document 1).
[Patent Document 1] Japanese Patent Application Laid-Open (Kokai) Publication No. 2005-141943